Balance throttle-valve



(No Model.) W. A. PENDRY.

BLANGB THROTTLE VALVE.

lINTTa STnTns -ATENT @Tricea IVILLIAM ALLEN PENDRY, OF DETROIT, MICHIGAN.

BALANCE TH ROTTLIEAALVE.

SPECIFICATION forming part of Letters Patent Application filed January 20, 1886, Serial No. IHM-207.

To all, whom if; may concern:

Be it known that l, WILLIAM ALLEN Pn DRY, of Detroit, in the county of NVayne and State of Michigan, have invented a new and useful Iinprovement in Balance -Valves, of which the following is a specification.

rEhis invention 'has for its object to provide a noveland efficient balanced throttle-valve which closes with the pressure of the iiuid to be controlled; and it consists in the construe tion and combination of devices, hereinafter described and claimed, reference heilig made to` the accompanying drawings, in which- Figure I is a central vertical sectional view of a valve embodying my invention, and Fig. 2 a similar view showing a modification.

IReferring to the drawings, the letter A represents the shell or casing o f a valve, which ditfers in shape according to the kind ot'valve desi redas globe, angle, straight-way, 85e.

i3 represents the valve-seat, formed in or on the shell in any known way, and C represents an ordinary cup-valve adapted to close seat B.

C representsa piston supported within the valve C, and may tit said valve stea1n`-tight or loosely, a's preferred. The manner in which said piston is supported is immaterial, so long as it is held up vwithin the valve; and I have shown means for accomplishing this end a stem, d', secured to the inside ofthe shell below the seat B, and rising through said seat the wings J J, secured to the inner side of the shell below the valve-seat B, extending up through said seat and carrying the piston on their npper ends. These wings and the piston also serve as guides for the valve C.

My invention is designed to apply to valves which close with the pressured-steam or water-which they control, and I represents a passage which leads from the steam side ofthe valve to the space between the valve and piston. IThe mouth of this passage I is formed into a valve-seat adapted to be controlled --by I a secondary valve, H.

rEhe passage I is located at one side of the main valve and passes up through the piston. represents a secondary valve adapted to No. 360,170, dated March 29, 1887.

(No model.)

control the passage I, and the main and' seeondary valves are to be so connected with the lifting mechanism employed, which may be of any known kind, that the secondary valve II will open'before thc main valve C opens. The mechanism which I have illustrated for this purpose is a liftinglcvcr, IV, fulerumed at one end, T, to a fixed support, S, and at the other endfl", to a counecing'rod, X.

The valve II is provided with a stem pivoted to the lever NV by a pin, U, which passes through the lever and through slots V in the upper end of adrig on the crown of the valve C, whereby the motion of the lever W` first lifts valve II and then lifts valve C.

rlhe operation of my invention is as follows: IVheu thelifting mechanism is operated to open the valve, the valve II opens Yfirst and steam rushes through passage I into the space between the main valve C and the piston, and exerts an equal pressure upon both sides of the crown of the main valve, so that saidvalve is only held to its seat hy the pressure of steam on the area of the annular ring of said valve, which is slight and easily overcome, so that the main"valve can be easily opened; and as the secondary valve H is of small area, it can be easilyopef-led against a high steam-presso re. In closing, lthe main valve seats first, but without shock, for it is so nearly balanced, and is firmly pressed to its seat as soon as the secondary valve closes. l

What I claim as my invention, and desire to secure by Letters Patent, isd

The combination, with a cup-valve, of a pistn rigidly supported within the valve and havingasteam-passageleading throughitssupporting-stem io the steam-space of the boiler, a secondary valve adapted to close said steampassage, and lifting mechanism connected with the secondary valve and cup-valve, whereby the Vsecondary valvelifts before the cup-valve, substantially as described.

YV. ALLEN IENDRY.

Witnesses:

SUMNER CoL'LiNs, v Guo. H. Lornnor. 

